Deciduous Azalea viscosum AGM

Widely known as the 'Swamp Honeysuckle'. This plant has beautifully scented white honeysuckle type flowers in June to July. It is a very hardy plant that likes moist soil. Nice autumn foliage colour. Height 120-150cm in 10 years. It prefers a fairly sunny position.

• Recommended for wonderful late fragrant flower.
• Easy to grow.
• Ideal position: most garden situations, likes some sun.
• Habit: upright.
• Group: Deciduous Azalea.
• Subsection: Pentanthera.
• Introduction date: pre 1900 (1680)
• Species distribution: Maine and Vermont, southwards to SE Texas to Florida.
• Approximate altitude: Sea-level to 1,500m.
• Ideal soil: pH 4.5 to 6.
• RHS Hardiness Rating: H6.
• How we usually propagate this plant: Seed.
• Awards: RHS Award of Garden Merit.

Customer Reviews

By TomBorg on 19th February 2024

"Delighted with the Azalea, good size and profusely budded, arrived in first class condition."

By Elaine McAllister on 6th October 2023

"As this was the first time I had bought from Millais Nurseries I was not sure what to expect but I needn't have worried. I received an excellent sturdy azalea, much better then I could have hoped for. It was well packaged and arrived undamaged. Millais kept me informed from order confirmation,when it was dispatched, and delivery/tracking. What more could you want. I highly this seller and will buy from the again without hesitation. "

By Melanie Gajic on 11th June 2022

"Absolutely lovely plant ! Superbly packages and fast delivery, highly recommended. "

By GlynisPennington on 27th January 2022

"The two azaleas arrived really well packaged and in superb condition. They were also much bigger than I expected. I would recommend buying plants from this company. I’m now looking forward to spring to see them in flower ???? "

By DeborahIve on 24th April 2021

"Beautiful specimen, delivered promptly in perfect condition "

By MarkDobell on 12th April 2021

"Outstanding Azalea "

By Maggie Cove on 4th June 2020

"My lovely Azelea arrived promptly and snuggly wrapped so none the worse for it's journey. The plant was full of bud all of which have continued into beautiful blossom. This is the 2nd Azalea I have bought from this company and would highly recommend them."

By Robert Nisbet on 19th June 2019

"Very pleased. Another large plant delivered in excellent condition with ongoing good health."

By Ivor Thomas on 10th May 2019

"Website was easy to navigate-lots of detail about individual plants. Checking out was easy and delivery prompt. The plant was well packed and suffered no damage. The plant was in first class condition and I will certainly order again."

Good to know

From a botanical point of view, deciduous azaleas are part of the rhododendron family, but typically they only have 5-7 stamens in the flowers instead of 11-13 stamens present in other rhododendrons. They make a dazzling display, particularly in yellows, oranges and reds, but can also be very subtle in shades of pink and white. They are tough and fast growing plants typically reaching 125-150cm in 10 years. Our selection ranges from the discreet small flowered species and Ghent varieties, to the bold large flowering Knaphill and Exbury types. Many have the added value of a good scent in spring, and fiery autumn colours before leaf fall. Our newest introductions greatly extend the season into late June and July.

Deciduous azaleas have a stronger root system and will tolerate poorer conditions and a slightly higher pH than other rhododendrons. They can be grown in soils up to pH 6.5 when plenty of ericaceous compost is added. They prefer light dappled shade, but can also be grown in sun or more shade. In sun, the plants will be bushier and lower, with more flowers, but these will not last so long. In shade, the plants will be taller, with fewer flowers, but these will last longer.

All require good moist ericaceous soil with a high organic content. For a guide to plant spacing, use the height we give in 10 years as a guide to the distance between each plant, or approximately 1 plant per 1.5m². Plant no deeper than the top of the rootball, and dig in plenty of good ericaceous compost around the sides.  A teaspoon of slow release feed is sufficient for a 3 litre plant, rising to a small handful for a mature plant.  They are tough plants, and tolerate growing in containers, where their flowers, scent and autumn colours can be appreciated. Re-pot every 3 years for best performance.

Please note: Plants supplied in winter months can look quite bare and stick-like, and may be pruned back to encourage more branching. This is normal, and they will soon fill out in the spring.


For further advice, For further advice, see here

Size Guide

picture for example only

The Basics

Ideal soil

Acidic soil, good organic content, pH 4.5-6.0. Inkarho range of rhododendrons will tolerate soils up to pH7.5

Sun or Shade

Light dappled shade is best for most varieties.

Shelter

Refer to hardiness rating. Give young plants protection.

Site Selection

Avoid close to trees, roots, invasive weeds, walls, hot patios, dry banks and waterlogged soils. Do not use weed matting or stone mulch.

Plant spacing

Use the height shown in 10 years as a guide to the distance between each plant. Allow room for plant to fill out. If planting closer for instant impact, be prepared to move plants after a few years.

Compost

• 3 litre pot, dig in 10-20 litres of ericaceous compost.
• 7.5 litre pot, dig in 20-30 litres of ericaceous compost.
• 70-80cm specimen, dig in 60 litres of ericaceous compost.
• 100-120cm specimen, dig in 120 litres of ericaceous compost.

Planting depth

Plant high in the ground, with the top of the rootball visible.

Feeding

Slow-release ericaceous feed recommended in March and straight after flowering.

Mulch

Recommended every few years.

Water

The key ingredient! Keep moist all season, especially the critical time at end of June for flower bud initiation. Tap water is better than no water. Heavy dose at least once per week in dry weather.

Drainage

Ensure good drainage in winter, especially with yellow flowering varieties. Avoid waterlogged sites.

Pruning

Rhododendrons and Camellias: Not normally required. Tidy wayward shoots after flowering.

Evergreen azaleas and Bloombux can be clipped into a low hedge.

Magnolias and Acers: Formative pruning when young to shape into a tree or bush.

Deadheading

Remove old flower-heads, particularly on young or weak plants.

For further advice see here

Delivery & Returns

Our website calculates the delivery charge according to weight and delivery location throughout the UK. To see these charges, please enter your postcode at the checkout, and you will see the charge vary as you add more items to your wheelbarrow.

Please see here for delivery information

Please see here for cancellation and return information